1. Field of the Invention
The present invention relates to an electromagnetic relay that opens and closes an electrical circuit.
2. Description of Related Art
A conventional electromagnetic relay described in JP-A-2005-203290 has a fixed contact and a movable contact. The fixed contact is located and supported at a predetermined position by a fixed contact support, and the movable contact is mounted on a movable body that is actuated by an electromagnetic force of a coil. The above configuration brings the movable contact and the fixed contact into contact with each other, and also separates the movable contact from the fixed contact such that the electrical circuit is opened and closed. Also, a case has a housing space that receives therein components, such as the coil, and the housing space is communicated with an external space of the case through a ventilation hole formed at the case.
However, when the conventional electromagnetic relay having the ventilation hole is used in a condition, where combustible gas is generated, combustible gas may enter into the housing space through the ventilation hole, and thereby combustible gas that has entered into the housing space may be ignited by electric arc generated between the movable contact and the fixed contact. If the generated flame may spread to the external space of the case through the ventilation hole, combustible gas in the external space of the case may be ignited disadvantageously.